An Isolated Hope: Seishū Hanaoka

Seishū Hanaoka

Have you ever wondered how anesthesia came about? How did that first anesthetist know the perfect amount to make someone completely unconscious, yet not dead? Better yet, who would trust their doctor enough to be the first person to be put to sleep?

Seishū Hanaoka, born in 1760, is known as one of the best doctors of the Tokugawa Shogunate of Japan. By studying the anesthetic work of third century Chinese physician Houa T’o, Hanaoka was driven to make “Tsusensan,” a concoction of Chinese and Japanese herbs that he boiled in alcohol and orally administered to patients before surgery (Source 3). Forty years would pass before Western medicine would integrate nitrous oxide, carbon dioxide, ether, and chloroform as their first general anesthetics.


The Tokugawa Shogunate, ranging 1603-1867, implemented a policy of “sakoku” (鎖国) meaning “locked country.” An isolationist policy, sakoku closed Japan’s borders and severed foreign ties, mainly to combat what had been the beginning of Western colonialism (Source 9). Western advances were therefore unknown and disregarded by many Japanese, save for a few Dutch allowances (the Dutch East India Company was given access to Nagasaki) (Source 7). The surgical progress credited to the Dutch was combined with Chinese herbal medicine in Hanaoka’s work. Following his studies in Kyoto, notable Dutch items at Hanaoka’s disposal were syringes, surgical knives, scissors, a spatula, needles, clamps, a mirror, and catheter tubes.


In the footsteps of China’s Houa T’o, who used datura stramonium and alcohol, Hanaoka used datura alba Nees, a household plant, which he mixed with alcohol. In The Doctor’s Wife, written in 1978 by Sawako Ariyoshi, there were stories of Hanaoka’s experiments, with an emphasis on the subservient role of women under the feudal Tokugawa Shogunate. In one passage, told from his wife Kae’s perspective, Hanaoka forced a cat’s face into a bowl of alcohol until it started to choke. When Hanaoka needed a human subject, he served Kae (a willing volunteer) a strong alcoholic drink, sending her into a three-day coma, followed by permanent blindness (Source 3). 


Hanaoka’s Tsusensan contained scopolamine, hyoscyamine/atropine, aconitine, and angelicotoxin. The combination of these ingredients induced anesthesia, as well as amnesia, sleep, and paralysis. The active ingredients atropine and scopolamine are used as sedatives and muscle relaxers; namely, ophthalmologists use atropine to this day to dilate pupils and scopolamine is administered before surgery to decrease saliva (Source 6).

One of Hanaoki’s manuscripts, “Nyugan Bensho” reveals that seven grams of the following herbs were added to 360 mL of boiling water and gently shaken for a few minutes:

Following preparation, the patient would drink Tsusensan on an empty stomach early in the morning. Unconsciousness and numbness were expected to be felt 2-3 hours afterwards, and expected to last for around 5 hours. Hanaoka also developed solutions to help bring them out of that state after surgery (Source 10).

In addition to herbal anesthesia, Hanaoka cited traditional Chinese treatments in his use of acupuncture and moxibustion (Source 5). Moxibustion, a traditional Chinese 

medical practice dating to 581 BCE, is the use of moxa (dried mugwort leaves), applied on or near the skin, aiming to induce blood flow and force out pathogens. Often, specific acupuncture points would be heated via moxibustion (Source 11).


Eventually, after 20 years of perfecting the dosage and measuring the effects (usually experimenting on dogs), Hanaoka applied his anesthetic concoction to breast cancer surgery; his 1804 use of Tsusensan in a partial mastectomy was the first documented use of general anesthesia. Going on to perform over a hundred surgeries, cancer became the field that propelled his career as a surgeon (Source 8). A collection of drawings ordered by Hanaoka, called “A Surgical Casebook,” (interactive book found here), pinpointed the medical problem for each person, which, more often than not, was a tumor.

The process of lumpectomy as depicted by the Hanaoka School, Naitō Museum of Pharmaceutical Science and Industry (Source 5)

In “Nyugan Bensho,” a manuscript, Hanaoka himself described the process of tumor removal, as performed during that first 1804 lumpectomy:

 “The cancerous mass is exised with a curved knife modified by myself, then the wound cavity is washed with ardent spirits (alcoholic solution) to clean and sterilize. Drains of cotton threads are inserted into the cavity, then the wound surface is closed by suturing carefully and an ointment made of coconutoil is applied on the suture-line”

-Seishū Hanaoka, “Nyugan Bensho” (Source 9)

Hanaoka School’s breast cancer lumpectomy depiction (Source 9).


In 2004, an anesthesiologist from Hirosaki University administered the prescription described in “Nyugan Bensho.” His subject became “excitable,” then unconscious, after just 40 minutes. Similar to the narcosis induced in today’s medical practices, this unconscious state would last for 8 hours, but consciousness would be fully regained after 15 hours and dilation of the pupils would last for a week. Though with an unintended effect, this demonstrates the efficacy of Hanaoka’s tsusensan, a revolutionary advancement of the early nineteenth century (Source 10).

“Brought to Life”: Seishu Hanaoka (Source 1)


Many of the sources of Hanaoka’s work, including the casebook above, were not produced by the doctor himself. His students, to which he taught Hanaoka-style general anesthesia, documented his methods, a few published after his 1835 death. Drawing evidence from the casebook, “Mafutsuto-Ron” (“Treatise on Mafutsu-san”) and “Yohka-Hiroku” (“Secret Records of Surgery”), a few scientists from the Japanese Society of Anesthesiologists were able to come to several conclusions in 2014:

  • Patients were blindfolded with limbs constrained during surgery
  • Physicians oversaw the surgeries, taking pulses and observing the patients’ progress (Source 4)

Resection of a testicular tumor using the Hanaoka Method, with blindfold and limb restriction (Source 4).

Additionally, as the focus shifted from efficacy to patient comfort, three symptoms became telltale signs of an effective dose of anesthesia:

  1. Pollakiuria (increased urination) and tachycardia (rapid heartbeat)
  2. Increased heart rate and xerocheilia (dry lips)
  3. Dilation of the pupils (Source 4)

Hanaoka founded a private medical school, Shunrinken, wherein he trained around 1300 students. The academy carried on his work and recorded his progress, though Japan’s political status prevented foreign dissemination (Source 10).


Though Hanaoka’s success in developing an herbal anesthetic preceded CW Long’s use of ether anesthesia in the United States by 38 years, Western anesthesia has come to dominate medicine, largely consisting of intravenous drugs and inhaled gases. These not only run a risk of addiction, but have allowed for domination by a few pharmaceutical companies. I wonder where medicine, specifically anesthesiology, would be today, had innovative drugs like Tsusensan become standard.






4 Dote, K., Yorozuya, T., Ikemune, K. et al. J Anesth (2015) 29: 96.





9 Kotler, D. L., B.A., Hirose, H., M.D., Yeo, C. J., M.D., & Cowan, S. W., M.D. (2014). Dr. seishu hanaoka (1760-1835): Surgeon, pharmacist, and anesthesiologist.The American Surgeon, 80(1), E7-9. Retrieved from




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